Topical corticosteroids can't cure these conditions, but can help relieve the symptoms.

Who can use topical corticosteroids

Most adults and children can use topical corticosteroids safely, but there are situations when they aren't recommended.

They shouldn't be used if:

you have infected skin – unless advised by a doctor

you have certain skin conditions including rosacea, acne and skin ulcers (open sores)

Most topical corticosteroids are considered safe to use during pregnancy or breastfeeding. However, you should wash off any steroid cream applied to your breasts before feeding your baby.

However, very potent topical corticosteroids aren't usually prescribed for pregnant or breastfeeding women, or for very young children. Exceptions are sometimes made under the supervision of a dermatologist (skin care specialist).

How to use topical corticosteroids

Unless instructed otherwise by your doctor, follow the directions on the patient information leaflet that comes with your medication. This will give details of how much to apply and how often.

Most people only need to use the medication once or twice a day for a week or two, although occasionally your doctor may suggest using it less frequently over a longer period of time.

The medication should only be applied to affected areas of skin. Gently smooth it into your skin in the direction the hair grows.

If you're using both topical corticosteroids and emollients, you should apply the emollient first. Then wait about 30 minutes before applying the topical corticosteroid.

Fingertip units

Sometimes, the amount of medication you're advised to use will be given in fingertip units (FTUs).

A FTU (about 500mg) is the amount of medication needed to squeeze a line from the tip of an adult finger to the first crease of the finger. It should be enough to treat an area of skin double the size of the flat of your hand with your fingers together.

The recommended dosage will depend on what part of the body is being treated. This is because the skin is thinner in certain parts of the body and more sensitive to the effects of corticosteroids.

For adults, the recommended FTUs to be applied in one single dose are:

0.5 FTU for genitals

1 FTU for hands, elbows and knees

1.5 FTUs for the feet, including the soles

2.5 FTUs for the face and neck

3 FTUs for the scalp

4 FTUs for a hand and arm together, or the buttocks

8 FTUs for the legs and chest, or legs and back

For children, the recommended FTUs will depend on their age. Your GP can advise you on this.

Side effects of topical corticosteroids

The most common side effect of topical corticosteroids is a burning or stinging sensation when the medication is applied. However, this usually improves as your skin gets used to the treatment.

Less common side effects can include:

worsening of a pre-existing skin infection

folliculitis – inflamed hair follicles

thinning of the skin – this can make the affected skin more vulnerable to damage; for example, you may bruise more easily

stretch marks – which are likely to be permanent, although they'll probably become less noticeable over time

contact dermatitis – skin irritation caused by a mild allergic reaction to the substances in a particular topical corticosteroid

changes in skin colour – this is usually more noticeable in people with dark skin

excessive hair growth on the area of skin being treated

Side effects are more likely if you're:

using a more potent corticosteroid

using it for a very long time, or over a large area

The elderly and very young are more vulnerable to side effects.

If potent or very potent topical corticosteroids are used for a long time or over a large area, there's a risk of the medication being absorbed into the bloodstream and causing internal side effects, such as:

This is not a full list of all the possible side effects. For more information on side effects, see the leaflet that comes with your medication.

Reporting side effects

The Yellow Card Scheme allows you to report suspected side effects from any type of medicine you're taking. It's run by the medicines safety watchdog called the Medicines and Healthcare products Regulatory Agency (MHRA).